VDO

i'd say it's probably not ECU related, if you'd bumped a wire or hose off in the engine bay is more likely. 

The oil gauge requires three connections to function.
 
Ground to the body/back nut of the gauge. 12v+  Sender feed (resisted ground)  
If the ground to the body/back nut of the oil gauge isn't present, the oil gauge will deflect to full scale.
 
The fuel and temp won't do this.
 
Therefore, you should closely check the cluster main ground feed.  It normally connects to the body in the drivers kick panel area.  It's only held with one screw and can become flaky due to corrosion or loosening.
 
Failing that, check and tighten the small slotted nut at the back of the oil gauge.

The oil gauge requires three connections to function.
 
Ground to the body/back nut of the gauge. 12v+  Sender feed (resisted ground)  
If the ground to the body/back nut of the oil gauge isn't present, the oil gauge will deflect to full scale.
 
The fuel and temp won't do this.
 
Therefore, you should closely check the cluster main ground feed.  It normally connects to the body in the drivers kick panel area.  It's only held with one screw and can become flaky due to corrosion or loosening.
 
Failing that, check and tighten the small slotted nut at the back of the oil gauge.

Get hold of a volt meter and test them.
 
With engine off:  Battery should show between 12 and 13 volts.
With engine running at idle:  Battery should show 13.8 volts
With engine running at 2000 rpm:  Battery should now show 14.2 volts.
 
If the voltage doesn't change during idle and rev up, then the alternator is shot.
If the voltage changes during running, then the alternator is ok, but if the battery still shows low when engine is off, then battery is shot.
 
Next step is take it to a battery shop or Supercheap and have the battery LOAD tested to confirm.

Just give it a soak in some caustic for a day or so.
 
No scrubbing, no nothing.
 
And a super clean result.
 
Simples..!

Just give it a soak in some caustic for a day or so.
 
No scrubbing, no nothing.
 
And a super clean result.
 
Simples..!

Just give it a soak in some caustic for a day or so.
 
No scrubbing, no nothing.
 
And a super clean result.
 
Simples..!

I'm gonna be sick

The trim pot in the speedo is only for very fine calibration, not for correcting an error of 19 Kph.
 
If you try that, then the odometer will register incorrectly.
 
You need to fit the correct gear on the transducer on the gearbox.
 
How many teeth does your current gear have..? 
 
You say you are 19 Kph over, then you will need to get a gear that has 4 more teeth than your current one, and you will be a lot closer to correctness then.
 
For example, if your current gear is 15 tooth, then you will need a 19 tooth gear.  Ford parts still carry them.

Dealer "FITTED" maybe.
 
I was a Ford manager and I can tell you categorically that the wheels would come from the local tyre/wheel shop.
 
The dealer would take the car down the road to have them done, or the dealer would remove the wheels and the shop would pick up and deliver the wheels with tyres mounted, and nuts to the P.D. workshop and there they would be "fitted".
 
This was done either as a less expensive option at the customer's request, or when the dealer couldn't obtain stock of the original wheels from Ford.
 
Sometimes it was done by the dealer to dress up old stock vehicles, ex demos and slow movers.

Hmmmmm.

http://www.ebay.com.au/itm/Ford-XD-XE-Sundowner-Falcon-S-Pack-LH-Exterior-Rear-View-Mirror-Very-CLEAN-Unit-/161823981692?hash=item25ad76007c
 
http://www.ebay.com.au/itm/Ford-XD-XE-Sundowner-Falcon-S-Pack-RH-Exterior-Rear-View-Mirror-Very-CLEAN-Unit-/161823985290?hash=item25ad760e8a

http://www.ebay.com.au/itm/Ford-eb-ed-ef-el-xg-xh-15-alloy-wheels-xr6-fairmont-ute-tickford-/252062363906?hash=item3ab0167102
 
http://www.ebay.com.au/itm/Ford-15-x-8-globe-wheels-/201408680304?hash=item2ee4e49170

See my link above.

The 2 bolt starter should fit your 3 bolt housing.
 
The wire to the coil is there to give the coil a boost of current while cranking to help starting.
If you have a decent, newer coil, you won't need the wire to it anymore.  
Don't connect the coil wire to the starter wire,or it will back feed and keep running your starter... leave it off.

The 2 bolt starter should fit your 3 bolt housing.
 
The wire to the coil is there to give the coil a boost of current while cranking to help starting.
If you have a decent, newer coil, you won't need the wire to it anymore.  
Don't connect the coil wire to the starter wire,or it will back feed and keep running your starter... leave it off.

What's the wattage of your high beam lights..?
 
Just divide the wattage by 12 and that will give you the amps.

What's the wattage of your high beam lights..?
 
Just divide the wattage by 12 and that will give you the amps.

Gauge dropping on braking is also a poor ground issue.
 
The ground for the cluster connects to the body, behind the drivers kick panel.
 
Remove, clean, replace.
 
Better still run an additional ground to the dash from the metal behind the dash to the black wire on the instrument cluster plug.

You probably have poor grounding to the brake lights.
 
When the brake lights come on, they need to steal some ground from the light assembly and it's not enough to serve them all at once, so one or more of your indicators will die, causing the others to flash faster due to the reduced load on the flasher relay.
 
Get into your tail light assebmlies and clean up all the ground connections in the lamp holders and particularly the ground wires going to the car body.
 
Remove and clean the bulbs too (the metal parts).

Gauge dropping on braking is also a poor ground issue.
 
The ground for the cluster connects to the body, behind the drivers kick panel.
 
Remove, clean, replace.
 
Better still run an additional ground to the dash from the metal behind the dash to the black wire on the instrument cluster plug.

You probably have poor grounding to the brake lights.
 
When the brake lights come on, they need to steal some ground from the light assembly and it's not enough to serve them all at once, so one or more of your indicators will die, causing the others to flash faster due to the reduced load on the flasher relay.
 
Get into your tail light assebmlies and clean up all the ground connections in the lamp holders and particularly the ground wires going to the car body.
 
Remove and clean the bulbs too (the metal parts).

You probably have poor grounding to the brake lights.
 
When the brake lights come on, they need to steal some ground from the light assembly and it's not enough to serve them all at once, so one or more of your indicators will die, causing the others to flash faster due to the reduced load on the flasher relay.
 
Get into your tail light assebmlies and clean up all the ground connections in the lamp holders and particularly the ground wires going to the car body.
 
Remove and clean the bulbs too (the metal parts).

If I remember correctly, you might need to take the vents out from above (just flip the vent and there's a screw on each).
 
Remove the radio: Remove knobs, remove the retaining nuts and fascia plate, undo 2 screws at top left and right holding the bracket, pull out and unplug the radio.
 
Remove the climate control:  Remove climate control knobs, remove all securing nuts, remove facia, remove nuts securing the switches to the metal plate, then it should all come apart for easy inspection.  Don't mix up the switches and vacuum lines..!
 
PS.  Have fun putting the fascia nuts back on... grrrrrrr...!

Possibly a leaking vacuum switch.
 
This might help:
http://s1072.photobucket.com/user/cjcurtis13/media/Emissiondiagram2r.jpgoriginal_zps5arkr3ku.jpeg.html?sort=3&o=0